Nima WebClient configuration for timeouts and keepAlive (helidon-io#6971)

* Nima WebClient Shortcuts for timeouts
* WebClient config for keepAlive
* Implement build() in WebClient.Builder and introduce an abstract doBuild method.
This allows WebClient.Builder to run pre-build code to set the channel options from the default builder.

Slight re-org of WebClient.Builder:
 - move all package private methods at the bottom
 - add javadoc to protected methods

Update javadoc related to the default socket options builder.

---------

Signed-off-by: aserkes <andrii.serkes@oracle.com>
Co-authored-by: Romain Grecourt <romain.grecourt@oracle.com>

Author: aserkes

nima/http2/webclient/src/main/java/io/helidon/nima/http2/webclient/Http2Client.java

@@ -129,7 +129,7 @@ public Http2ClientBuilder prefetch(int prefetch) {
         }
 
         @Override
-        public Http2Client build() {
+        public Http2Client doBuild() {
             return new Http2ClientImpl(this);
         }
 

nima/webclient/webclient/src/main/java/io/helidon/nima/webclient/WebClient.java

@@ -17,8 +17,10 @@
 package io.helidon.nima.webclient;
 
 import java.net.URI;
+import java.time.Duration;
 import java.util.List;
 import java.util.Objects;
+import java.util.function.Consumer;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
@@ -69,6 +71,7 @@ abstract class Builder<B extends Builder<B, C>, C extends WebClient> implements
         private URI baseUri;
         private Tls tls;
         private SocketOptions channelOptions;
+        private final SocketOptions.Builder channelOptionsBuilder = SocketOptions.builder();
         private DnsResolver dnsResolver;
         private DnsAddressLookup dnsAddressLookup;
         private boolean followRedirect;
@@ -82,6 +85,21 @@ abstract class Builder<B extends Builder<B, C>, C extends WebClient> implements
         protected Builder() {
         }
 
+        /**
+         * Actual {@link #build()} implementation for {@link WebClient} subclasses.
+         *
+         * @return new client
+         */
+        protected abstract C doBuild();
+
+        @Override
+        public C build() {
+            if (channelOptions == null) {
+                channelOptions = channelOptionsBuilder.build();
+            }
+            return doBuild();
+        }
+
         /**
          * Base uri used by the client in all requests.
          *
@@ -131,6 +149,14 @@ public B tls(Supplier<Tls> tls) {
 
         /**
          * Socket options for connections opened by this client.
+         * Note that using this method will trump the default {@link SocketOptions.Builder}.
+         * Thus, all methods that operate on the default {@link SocketOptions.Builder} are ineffective:
+         * <ul>
+         *     <li>{@link #channelOptions(Consumer)} </li>
+         *     <li>{@link #readTimeout(Duration)}</li>
+         *     <li>{@link #connectTimeout(Duration)} (Duration)}</li>
+         *     <li>{@link #keepAlive(boolean)}</li>
+         * </ul>
          *
          * @param channelOptions options
          * @return updated builder
@@ -140,6 +166,17 @@ public B channelOptions(SocketOptions channelOptions) {
             return identity();
         }
 
+        /**
+         * Configure the socket options for connections opened by this client.
+         *
+         * @param consumer {@link SocketOptions.Builder} consumer
+         * @return updated builder
+         */
+        public B channelOptions(Consumer<SocketOptions.Builder> consumer) {
+            consumer.accept(channelOptionsBuilder);
+            return identity();
+        }
+
         /**
          * DNS resolver to be used by this client.
          *
@@ -185,6 +222,46 @@ public B maxRedirects(int maxRedirect) {
             return identity();
         }
 
+        /**
+         * Connect timeout.
+         * This method operates on the default socket options builder and provides a shortcut for
+         * {@link SocketOptions.Builder#connectTimeout(Duration)}.
+         *
+         * @param connectTimeout connect timeout
+         * @return updated builder
+         */
+        public B connectTimeout(Duration connectTimeout) {
+            channelOptionsBuilder.connectTimeout(connectTimeout);
+            return identity();
+        }
+
+        /**
+         * Sets the socket read timeout.
+         * This method operates on the default socket options builder and provides a shortcut for
+         * {@link SocketOptions.Builder#readTimeout(Duration)}.
+         *
+         * @param readTimeout read timeout
+         * @return updated builder
+         */
+        public B readTimeout(Duration readTimeout) {
+            channelOptionsBuilder.readTimeout(readTimeout);
+            return identity();
+        }
+
+        /**
+         * Configure socket keep alive.
+         * This method operates on the default socket options builder and provides a shortcut for
+         * {@link SocketOptions.Builder#socketKeepAlive(boolean)}.
+         *
+         * @param keepAlive keep alive
+         * @return updated builder
+         * @see java.net.StandardSocketOptions#SO_KEEPALIVE
+         */
+        public B keepAlive(boolean keepAlive) {
+            channelOptionsBuilder.socketKeepAlive(keepAlive);
+            return identity();
+        }
+
         /**
          * Configure a custom header to be sent. Some headers cannot be modified.
          *
@@ -200,7 +277,7 @@ public B header(Http.HeaderValue header) {
         /**
          * Set header with multiple values. Some headers cannot be modified.
          *
-         * @param name header name
+         * @param name   header name
          * @param values header values
          * @return updated builder instance
          */
@@ -249,24 +326,32 @@ public B mediaTypeParserMode(ParserMode mode) {
          *
          * @return socket options
          */
-        SocketOptions channelOptions() {
+        protected SocketOptions channelOptions() {
             return channelOptions;
         }
 
         /**
-         * Configured TLS.
+         * Default headers to be used in every request.
          *
-         * @return TLS if configured, null otherwise
+         * @return default headers
          */
-        Tls tls() {
-            return tls;
+        protected WritableHeaders<?> defaultHeaders() {
+            return defaultHeaders;
         }
 
         /**
-         * Base request uri.
+         * Media type parsing mode for HTTP {@code Content-Type} header.
          *
-         * @return client request base uri
+         * @return media type parsing mode
          */
+        protected ParserMode mediaTypeParserMode() {
+            return this.mediaTypeParserMode;
+        }
+
+        Tls tls() {
+            return tls;
+        }
+
         URI baseUri() {
             return baseUri;
         }
@@ -287,13 +372,5 @@ int maxRedirect() {
             return maxRedirect;
         }
 
-        protected WritableHeaders<?> defaultHeaders() {
-            return defaultHeaders;
-        }
-
-        protected ParserMode mediaTypeParserMode() {
-            return this.mediaTypeParserMode;
-        }
-
     }
 }

nima/webclient/webclient/src/main/java/io/helidon/nima/webclient/http1/Http1Client.java

@@ -81,11 +81,12 @@ private Http1ClientBuilder() {
         }
 
         @Override
-        public Http1Client build() {
+        public Http1Client doBuild() {
             configBuilder.defaultHeaders(defaultHeaders());
             if (mediaContextBuilder != null) {
                 configBuilder.mediaContext(mediaContextBuilder.fallback(configBuilder.mediaContext()).build());
             }
+            configBuilder.socketOptions(super.channelOptions());
             return new Http1ClientImpl(configBuilder.build());
         }
 

nima/websocket/client/src/main/java/io/helidon/nima/websocket/client/WsClient.java

@@ -82,7 +82,7 @@ private Builder() {
         }
 
         @Override
-        public WsClient build() {
+        public WsClient doBuild() {
             // these headers cannot be modified by user
             header(HEADER_UPGRADE_WS);
             header(HEADER_WS_VERSION);